The invention relates to an apparatus for bending, kinking and cutting to length the connecting wires of electrical components, with a storage container for the components, with at least one tool set comprising two tools which operate against each other and shape the connecting wires between them and are adapted for bending and kinking, with a conveying device which is connected to the storage container and is adapted to supply the components to the tool set, and with a cutting device for cutting the connecting wires to length.
Electrical components leave the production process with linear connecting wires which must be bent, kinked and cut to length for wiring and electrical connecting purposes. These operations can be performed relatively simply for cylindrical components in which the connecting wires extend from opposite end faces of the component, because as a rule these connecting wires are bent in one direction and are also provided with identical kinks. To this end, the prior art discloses devices (see U.S. Pat. No. 3,900,053) in which the components are taken up by the two connecting wires in the tooth gaps of gear-like conveying wheels arranged in pairs. The components are guided by means of the said conveying wheels past the forming and cutting tools.
By contrast, the present invention relates to the processing of components whose connecting wires do not appear coaxially at opposite sides of the component member but emerge adjacently on one side of the component member. By virtue of their asymmetrical construction, such components cannot be readily conveyed and supplied continuously to processing stations. Furthermore, the connecting wires must frequently be bent and kinked into different directions, which is also not possible with the devices described above. A device of the kind described initially is known from practical operation and is described in U.S. Pat. No. 4,206,539, in which said device one or more tool sets is or are disposed on the circumference of a support plate which is rotatable about a stationary axis and one of the tools can be pivoted about a pivoting axis, parallel to the axis of rotation, in relation to the second, stationary tool, and in the course of rotation of the support plate can be driven by a stationary disc cam from an open position into a closed position and back again. At a place of transfer to the circulating tools the conveying device is provided with a transfer slot which is disposed approximately at the height of the tools and extends in the circulating direction thereof and is open in that direction and each supporting one component which is to be transferred and whose connecting wires extend downwardly through the slot. Each of the components to be processed is transferred to one circulating tool set in the course of the circulation of which the connecting wires are being processed. Before the transfer operation, the pivotable tool is controlled by the disc cam so that, with the tools in the open position, the component, which is supported in the transfer slot, is gripped by the tool which trails in the circulating direction and the tools are subsequently closed.
This known device of the kind described hereinbefore has proved itself in excellent manner because, on the one hand, it permits exceptionally high processing capacities to be achieved and, on the other hand, allows simple changing of the tool sets without complicated adjusting operations. However, a plurality of identical tool sets is necessary on the circumference of the support plate in order to achieve such high processing capacities. Furthermore, relatively large masses must be moved so that a relatively high complexity is involved in the construction and in the drive and this can be regarded as detrimental in cases calling only for medium processing capacities.
An object of the invention is a device of the kind described hereinbefore, which can be embodied at low expenditure, more particularly has only small moving masses, but nevertheless permits high processing capacities to be achieved. The possibility of simple tool changing without complicated readjustment is of course to be retained.
According to the invention, the problem is solved in that the tool set is arranged to be stationary (i.e., naturally stationary in relation to the machine casing) or simply reciprocable and is associated with a stationary component guide, that the component guide comprises a guide way with a guide slot and the connecting wires extend through the guide slots and project downwardly into the operating range of the tool set and that the tools of the tool set can be adjusted along a plane which is perpendicular to the guide slot, and moved in a direction which is perpendicular to the guide slot. According to one preferred embodiment, the component guide is associated with a friction drive for the components. A plane, extending parallel with the plane of the boundaries forming the guide slot, is described as being perpendicular to the guide slot. The guide slot, which is provided in accordance with the invention and is usually constructed in rectilinear form, must not be confused with the conveying means, also constructed in slot-shaped manner, and disposed between the storage container and the processing station, which said conveying system is present in the known device as well as in the device according to the invention. The component guide according to the invention with guide slot is provided to retain and guide the components during the processing operation by contrast to the known device in which the components are retained and guided solely by the tools during processing. Transfer of the components in the component guide, i.e., in the actual operating range of the tools, is preferably performed in accordance with the invention by a friction drive. A drive (provided, e.g., by a vibrator or by a friction drive) can of course also be provided in the region of the conveying system. As regards the friction drive which may be provided in accordance with the invention and will be explained hereinbelow in detail, it is essential in every case that the components are conveyed not by positive engagement with the drive element, but solely non-positively, e.g., by frictional engagement in the guide way. Such a friction drive does not interfere with the processing operation during which the components must be stopped, at least briefly, because, owing to frictional engagement, the friction drive simply continues to operate with slip while the components are stopped. The tools, e.g., arranged in stationary configuration, can be readily preadjusted as a complete tool set and can be attached to the device according to the invention, so that tool changing for the purpose of changing to a different processing function, can be performed in a simple manner.
Advantageously, such a friction drive has at least one drive element in the form of a rotatingly driven friction roller or of a circulating friction belt which imparts a feed force to the components in the direction of the guide slot. The surface, which acts on the components, of the friction roller or the friction belt has a frictional characteristic which ensures reliable feeding of the components. To this end, they can be constructed of rubber, soft plastics or foam material or they can have a friction-increasing covering of rubber, foam substances or the like. Furthermore, the frictional roller or the friction belt can be constructed as a brush roller or can be provided with a brush covering.
It is possible to provide only one driving element which acts on the top of the component members and functions simultaneously as work holder to thrust said components against the guide way. It is also possible to provide two driving elements which act on opposite sides of the components, either on the connecting wires or preferably on the component member. This embodiment is particularly recommended if the component member is relatively tall and narrow and, therefore, bears with only a narrow surface on the guide way.
In order to adjust the connecting wires to different lengths, it is recommended to arrange the tool set on a drive block which can be raised and lowered in relation to the guide slot, more particularly by being guided on guide rods and being vertically adjustable by means of a spindle which is fixed to the machine.
Different means are available for arranging and actuating the tools of the tool set. On the one hand, one of the tools can be arranged fixedly with respect to the machine and the other tool displaceable relative thereto. This permits a particularly simple means of performing tool actuation. To ensure trouble-free insertion of the connecting wires into the tool, which is fixed to the machine, it can be advisable for a ramp, inclined in relation to the conveying direction, to be arranged upstream of the said tool. On the other hand, both tools of the tool set can be adjustable relative to each other. Symmetrical operation of the tools is desirable so that, in the end position, the parting joint between the closed tools, which mesh with each other, is situated symmetrically beneath the guide slot. The tools can be actuated in conventional manner by a motor with an eccentric, disc cam or the like or by means of a plunger magnet or solenoid.
The tools can be opened after each operation by means of an opening spring against whose action the tools are moved into the closed position. To overcome the inertia of the tools at higher operating speeds, it may be necessary to provide an opening with an undesirably high spring force. Positive opening of the tools by the tool drive is recommended, at least in such cases.
It is possible for the bent and kinked connecting wires to jam in the tools without being readily released. This defect can be overcome by combining one of the tools with an ejector lever by means of which the components are ejected from the second tool after processing when the tools are opened. By suitable design of tools, it is possible to achieve the preferred case in which the components are forcibly ejected from the tool which is fixed to the machine and, accordingly, the ejector lever is coupled to the adjustable tool. In some circumstances both tools can be provided with ejector levers which are alternately coupled to each of the second tools.
Satisfactory synchronization of the component feed in the guide way with the operation of the tools is of particular significance for functioning of the device according to the invention. In one method to achieve this end the guide slot is associated with a movement monitor in the form of a photoelectric barrier, a proximity switch or the like, and operation of the tool set is triggered by the movement monitor. Another possibility, characterized by its great simplicity, consists in associating the guide slot with a component trap having at least one separating slide, which can be inserted in the guide slot, and by arranging for actuation of the separating slide by the drive of the tool set. The separating slide can be arranged either as a stop slide behind the tools and/or it can be arranged upstream of the tools in the form of a release slide. With due allowance for the conveying speed of the friction drive, control of the stop slide and of the tools with respect to time can be arranged, so that the tools are closed only when the appropriate component bears, in the predefined processing position, against the stop slide. It is also possible to construct the stop slide as an actuating element of a switch by means of which tool actuation is triggered when a component bears upon it. Satisfactory results can also be achieved solely by means of a release slide arranged upstream of the tools, if tool actuation is triggered with corresponding delays after removal of the release slide from the guide slot, with due allowance to the conveying speed of the friction drive. Combining the stop slide and the release slide into a "trap" in the narrower sense has also been found advantageous in some cases.
Different means are available for embodying the tools, depending on the kind of components which have to be processed. A compact, closed tool set by means of which the connecting wires are spread apart, bent and kinked in accordance with the pitch of the circuit into which they are to be inserted, is recommended for transistors or the like whose connecting wires emerge from one side of the component. The corresponding construction of the tools is described in detail in the applicants' U.S. Pat. No. 4,206,539.
The apparatus according to the invention can also be advantageously used for processing components whose connecting wires emerge coaxially from opposite sides of the component member. Components of this kind can be processed with the known device, which was initially described, but only in a manner in which the kinks on both connecting wires extend in the same direction. In practice, it has been found that components provided with kinks in this manner are not positioned accurately vertically in the desired manner when they are inserted into the connecting apertures of a circuit board. This defect can be eliminated by providing the connecting wires with kinks oriented in opposite directions. This can be achieved by initially bending the connecting wires in the same coplanar direction from the component member and by processing them with the device according to the invention. In accordance with the distance between the connecting wires, which said distance will then be relatively large, each of the tools are constructed with two tool portions which cooperate in pairs and are situated at a corresponding and, where appropriate, adjustable distance in the direction of the guide slot. One tool portion, more particularly, the front tool portion, of each tool can be constructed in relatively narrow form, since the position of one of the connecting wires can be correspondingly accurately predefined for the processing operation. The second and, more particularly, rear tool portion of each tool will have a greater width in accordance with the varying distance of the connecting wires, which said distance depends on the size of component and on the particular case. This ensures that both connecting wires are reliably gripped by the tools. Proceeding therefrom, the two connecting wires can readily be provided with oppositely oriented kinks in that the tool portion regions, adapted to form the kinks (usually an indentation of a tool portion and a projection of the second tool portion adapted to engage with the former), are arranged in opposite configuration on the front and rear tool portions.
The connecting wires can be cut to length in a simple manner by providing the underside of the tools with shearing tools. Usually, shearing tools can be rigidly connected to the bending and kinking tools because the necessary distance between the kink and the wire ends is substantially defined only by the thickness of the circuit board and, in practice, is hardly ever subject to change. Where appropriate, the vertical distance of the shearing tools from the bending and kinking tools can also readily be made adjustable. Another method is to provide a separate cutting device upstream or downstream of the tool set comprising the bending and kinking tools and, to this end, the guide slot is extended without interruption, at least as far as the cutting device. A construction described in U.S. Pat. No. 4,276,796 is recommended for such a separate cutting device which substantially provides two shearing wheels, each provided with a circumferential cutting edge, of which at least one shearing wheel is rotatably drivable and is provided with a serration.
Unless special precautions are taken, there is a risk of tensile stresses loosening the connecting wires in the component member when said connecting wires are processed by bending and kinking. This can be remedied by applying pull relief to the connecting wires when they are being processed. The provision above each of the two tools for bending and kinking of a holder or work holder adapted to clamp the connecting wires of the component directly beneath the component member is one possibility of applying such pull relief, both of the two holders or work holders being supported so as to have limited movability relative to their associated tool under the action of a spring and of a stop abutment in such a way that, during the closing motion of the pivotable tool, the holder associated therewith is entrained until it bears upon the work holder and subsequently (while clamping the connecting wires) and at the commencement of the actual operating motion the work holder is also entrained against the action of the spring supporting the same and finally, when the holder and work holder are at rest, the pivotable tool is moved into the limiting position against the spring which supports the holder while the connecting wires are bent and kinked. This has already been described in detail in the previously mentioned U.S. Pat. No. 4,206,539 of the applicant.
Providing adjustability for a portion of at least one of the boundaries of the guide slot in the region of the tool set with respect to the second boundary is another possibility of achieving pull relief and is characterized by particular simplicity and reliability within the scope of the present invention. In such a system, the boundaries of the guide slot are also used as clamping jaws to provide pull relief. Adjustment of the corresponding portion of one or both of the boundaries of the guide slot is of course performed until the connecting wires are clamped, namely, in synchronism with the operation of the tools, more particularly, by the tool drive itself. To maintain a specific predefined clamping force, it is advisable to allow the drive to act on the corresponding portion of the guide slot boundary not directly but via a spring of a predefined spring force.
To reliably avoid pull being applied to the connecting wires of the components, an effect which could lead to damage of the components due to loosening of the connecting wires under unfavorable circumstances, another embodiment provides that the tool set is reciprocable within an operating range (operating motion), that the closing motion is synchronized with the operating motion so that, during the portion of the operating motion, which takes place in the conveying direction, the tools are closed and they are opened in the opposite direction and that the guide way terminates in the operating range of the tool set. The invention, therefore, ensures that the tool set is not completely fixed in relation to the component guide but performs a reciprocating operating motion within an operating range which is stationary with respect to the component guide. In this system, the components are transferred not by a friction drive, but by virtue of the fact that the components are gripped by the tools, are removed from the component guide which terminates in the operating range of the tools and the component connecting wires are processed outside the component guide. This does not, of course, dispense with the need for the components to be supplied in suitable manner to the operating range, for example, by the action of gravitational force in the component guide which is arranged at a slope. It is, of course, also possible to provide an additional friction drive. In every case it is essential that, during processing, the components are transferred to the tools by virtue of the latter being closed at or after the front dead centre of the operating motion and processing takes place while the tools perform the operating motion stroke which extends in the conveying direction and at the end of the said stroke the tools are again opened and the processed components are ejected.
The operating motion and the closing motion can extend parallel with each other and, jointly, substantially perpendicular to the orientation of the guide slot. In this case, a transfer slot, which is parallel with the operating motion, is disposed downstream of the guide slot. It is, however, particularly advantageous if the operating motion is arranged parallel with the guide slot and substantially perpendicular to the closing motion of the tools. Advantageously, the operating motion of the tools is performed so that the latter are adjustably supported on a slide which can traverse in accordance with the operation motion in a slide way which is stationary with respect to the guide way. The operating motion can be imparted to the slide, for example, by a hydraulic or pneumatic cylinder-piston system or by means of a connecting rod from a rotating motor. At least one of the tools is adjustable with respect to the slide. This adjustment can be performed by arranging for the tools to be linearly adjustable by means of suitable guides or preferably by supporting the tools pivotably. To this end, it is advisable if, initially, the tools are fixedly mounted on corresponding tool holders which, in turn, are adjustably supported on the slide. The closing motion of the tools is made possible by the adjustable support of the tools or tool holders and can be performed, for example, by means of at least one plunger magnet and energization of the plunger magnet can be controlled by control switches which are actuated by the tool set or by the slide via control cams mounted thereon and disposed along the operating range. Correspondingly, the closing motion can be performed by hydraulic or pneumatic cylinder-piston systems whose control elements are actuated by switch cams associated with the tool set or the slide. In another method, which is characterized by particular simplicity, the closing motion of the tools is performed by at least one disc cam which is disposed along the operating range and at least one of the tools, namely, the tool performing the closing motion, i.e., both tools if both are adjustable, are connected to a control finger adapted to cooperate with the disc cam. Advantageously, each control finger or plunger magnet acts on the tool support. It is usually advisable for both tools to be adjustable within the range of the closing motion. This applies particularly to the previously-explained case in which no additional transfer slot is provided and the operating motion is performed in a direction which is parallel with the guide slot of the component guide. Accordingly, in this case, two disc cams are provided of which each controls one of the tools.
After processing, the tools can be opened by being biased by an opening spring in a direction opposite to the closing motion. In this case, each of the disc cams will have only one control cam, namely, a closing cam. Another method, particularly advantageous for high operating speeds, consists of the disc cams having an opening cam and a closing cam. In this case, the control fingers will be guided by the cams over a closed path. so that the tools are moved in the closed position in the conveying direction and in the open position in the opposite direction.
When using pull relief elements in the form of holders and work holders disposed above the tools, as already explained above, each bearing, by means of a spring on the corresponding tools and being supported so as to have limited movability, it is advisable for the tools to be vertically adjustable in relation to the slide, independently of the pull relief elements. This ensures that the components are always gripped and retained by the pull relief elements in the same position while the position at which the connecting wires are kinked and bent can be set for vertical adjustment of the tools.
With respect to individualizing the components and transferring them to the tool set, it is advisable that, at the region which is at the rear of the device, a separating slide is fixedly connected to at least one of the tools and/or pull relief elements. This ensures that, when a component is gripped between the tools, the succeeding components are retained by the separating slides so as to obviate any faults during transfer. This embodiment is recommended particularly if the operating motion is performed parallel with the guide slot.
It is also advisable to close the end of the guide slot by a spring-biased locking element by means of which each leading component is retained in a defined position for transfer to the tools. During transfer, each such component is obtained while overcoming the spring force. The locking element can be constructed, for example, as a simple leaf spring associated with a cam which projects into the slot.
Since the components, whose connecting wires have been processed, are ejected generally no later than the end of the operating motion of the tools, it is advisable that the connecting wires shall have been cut to the specified length no later than that time. To this end, corresponding cutting tools can be directly associated with the tools for bending and kinking, as already described above. A cutting device, which is disposed beneath the guide slot upstream of the tools in the conveying direction and is preferably adapted to be independently and vertically adjustable in relation to the component guide, represents another particularly advantageous possibility.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.